using System;

//Professor Class

public class Professor

{

    // [Code] Define Fields

    public string ProfName;

    // [Code] Define Property Age

    // Make sure Age is between 18 and 70

    // If Age violates the rule, set the default value as 30

    private int privateAge;

    public int Age

    {

        get { return privateAge; }

        set { 

            if (18 <= value && value <= 70)

                privateAge = value; 

            else 

            {

                int defval = 45; 

                Console.WriteLine("Warning: {0} is not a valid Age. Setting age to default value {1}", value, defval);

                privateAge = defval;

            }

        }

    }

    // [Code] Define Property Degree

    // The degree's value should only equal to "master" or "phd".

    private string dg;

    public string Degree

    {

        get { return dg; }

        set {

            if (value == "phd" || value == "master")

                dg = value;

            else 

            {

                const string defval = "master"; 

                Console.WriteLine("Warning: {0} is not a valid Degree. Setting Degree to default value {1}", value, defval);

                dg = defval;

            }

        }

    }

    // [Code] Constructor

    public Professor()

    {

    }

}

​

//Course Class

public class Course

{

    // [Code] Define Fields

    public string CourseName;

    // [Code] Properties CourseID

    // Make sure CourseID has exactly 4 characters

    private string id;

    public string CourseID

    {

        get { return id; }

        set {

            if (value.Length == 4)

                id = value;

            else

            {

                const int len = 4; 

                Console.WriteLine("Warning: {0} is not a valid CourseID. Has to be 4 chars long", value, len);

            }

        }

    }

    // [Code] Properties ClassLimit

    // Make sure ClassLimit is under 50

    private int limit;

    public int ClassLimit

    {

        get { return limit; }

        set { 

            if (value > 50) limit = 50;

            else if (value < 1) limit = 1;

            else limit = value;

        }

    }

    // [Code] Constructor

    public Course()

    {

    }

}

​

public class Program

{

    public static void Main()

    {

        //[Code] Create an object ProfessorTuna

        // ProfessorName: Tuna

        // Age: 99

        Professor teacher = new Professor();

        teacher.ProfName = "Tuna";

        Console.WriteLine("Prof Name is {0}", teacher.ProfName);

        Console.WriteLine("Prof Age is {0}", teacher.Age);  

        teacher.Age = 100;  

        Console.WriteLine("Prof Age is {0}", teacher.Age);  

        teacher.Degree = "diploma";

        Console.WriteLine("Prof's Degree is {0}", teacher.Degree);  

​

        //[Code] Create an object CourseS308

        // CourseID: S308

        // CourseName: C#

        // ClassCapacity: 21

​

        Course c = new Course();

        c.CourseName = "Bus App Dev";

        c.CourseID = "S30";

        Console.WriteLine("Course name is {0}", c.CourseID);

        c.CourseID = "S308";

        c.ClassLimit = -6;

        Console.WriteLine("Class limit is {0}", c.ClassLimit);      

        // [Code] Show professor's age and course capacity

        // What happens if the age is greater than 70?

    }

}